Low-water alarm



(No Model.)

' w. 1. PAGE.

LOW WATER ALARM.

Patented NovJlZ, 1889.

J1 M912 Z021 Pram FFICE.

ILIJIAIWI 1. PAGE, OF BOSTON, MASSACHUSETTS.

Low-WATER ALARM.

SPECIFICATION forming part of Letters Patent No. 414,990, dated November 12, 1889.

Application filed March 29, 1889. Serial No. 305,239. (No model.) 7

To all whom it may concern.-

Be it known that I, IVILLIAM I. PAGE, a citizen of the United States, residing at Boston, in the county of Suffolk and State of Massachusetts, have invented certain new and useful Improvements in Low-Water-Alarm Apparatus; and I do hereby declare the following to be afull, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had t the accompanying drawings, and to letters or figures of reference marked thereon, which form a part of this specification.

This invention relates to a certain. class of apparatus designed for use on steam generators or boilers of allkinds to indicate low water, as well as to cause an alarm whenever the water-supply is below a proper safetylcvel, and hence termed low-water alarms.

The object of this invention is to produce a device which shall occupy but a small space, and hence introduced equally well either in vertical or horizontal boilers; further, one which shall operate only when the water has fallen below a certain level or reached the danger limit. To this end I employ the devices hereinafter particularly set forth and,

claimed.

The drawings represent, in Figure, 1 a vertical sectional elevation of a low-water alarm embodying my invention. Fig. 2 shows its application to a horizontal boiler.

In said drawings herewith annexed, 2 represents a tubular rod exteriorly screwthreaded at the upper portion, which engages with a screw-tapped hole in the boiler-shell, to which it is further secured by nuts interiorly and exteriorly of said shell, or the exterior one may be dispensed with. A whistle 3 is screwed upon the projecting end portion,

said whistle being employed to sound an alarm whenever the level of the water within the boiler falls below a proper safety-mark. The lower central end portion of the whistle is beveled to form a cone-shaped seat 4, to receive a valve 5, formed at the extremity of a light tubular rod 6, which serves as the valvestem. This rod is provided in the upper portion with a transverse stop-pin 7, the latter engaging in diametrically-disposed openings 8 S in the fixed rod 2. The lower extremity of said valve-stem is furnished with an adjustable nut or stop 9, and also with a weighted float 10, adapted to move freely upon the valve-stem to enable it to rise or fall without ordinarily operating the valve. Thus the level of the water in the boiler may fluctuate; but so long as it remains at a height above the danger-level so long does the said float continue inoperative with respect to the valve. Exterior-1y of the fixed tubular rod 2 is mounted a movable collar 12, adjustable by a set-screw 13, while a coiled spring 14 is located and confined exteriorly of said rod 2 between the extremities of the stop-pin 7 and said collar. The latter, being a fixed point, serves to regulate the tension of said spring, which holds the valve 5 normally upon its seat.

In practice I find it desirable to construct the valve-stem of a light tubular rod, while the tension of the spring is just sufficient to prevent the valve 5 from allowing steam to escape. To render the said valve and valvestem balanced, I have perforated the stem at a point 15 which permits steam to surround it interiorly and exteriorly, even when the open lower end of said stem is immersed in the water.

The stop-pin 7 subserves a secondary purposethat is, when the water is drawn off from the boiler the valve and valve-stem are prevented from dropping down and out of the fixed rod 2, since the weighted float 10 would otherwise produce such result, having no liquid to support it, it being understood that the said float is always weighted sufficiently to open the valve against its spring when not supported by the water.

The operation of this low-water-alarm apparatus is as follows, presuming that the several component parts are as shown in Fig. 1- that is, the water-level is above the dangerpoint (shown by line 03 0c) and the valve 5 is closed, being held upon its seat by the spring 14:: The float is shown in Fig.- 2 some distance above the lower end of the valve-stem, and is free to rise and fall thereupon, according as the level of the water varies. The

position of the several (so-operating parts thus continues until the water reaches the danger-point, which depends upon the position of the stop 9 upon the Valve-stem. The latupon the whistle to produce an alarm.

ter may be varied in length and adapted to suit boilers of every description and size. In the present instance the danger-point should be a short distance above the uppermost fines; hence when the water reaches that point the float 10 drops, contacts with the stop 9, and is unsupported by the water. The weight of the float is now exerted by gravity to counteract the spring 14, and the valve is opened, when steam escapes and acts Immediately upon an inflow of water and rise in the water-level the float is lifted and removed from contact with the stop 9, when the spring is relieved, and by its tension restores the valve to its seat, preventing further escape of steam and causing cessation of the alarm.

In the drawings I have shown the float as a hollow metallic shell provided with a diametrically-disposed sleeve 16, screw-tlnreaded at both ends, which engage, respectively, that portion of the sphere contiguous thereto. In this way I produce a hollow water-tight float with a central aperture, through which extends the valve-stem 6. Moreover, I have provided means by which the float may be weighted either exteriorly or interiorly. In the former instance the sleeve 16 extends a short distance below the float, whereby differentsized weights centrally bored and screw-tapped maybe removably affixed thereto. In the latter case or interiorly an aperture 17, closed with a screw-plug 18, is made through the shell of the float, and shot or other small metallic pieces may thus be i11- troduced to give the requisite weight to the float or removed therefrom, if necessary.

\Vhat- I desire to claim is 1. In low-water alarms, atubular rod fixed in the boiler-shell and the whistle or alarm apparatus upon said rod, combined with. a valve and valve-stem, the latter spring-actuated, the adjustable terminal stop 9 upon said stem, and the weighted float freely moving thereon and adapted, when in contact with said step, to open the valve, substantially herein stated.

2. In low-water alarms, a tubular rod fixed in the boiler-shell, the whistle or alarm apparatus upon said rod, and the adjustable collar, also thereupon intcriorly of the boiler, combined with a valve and valve-stem, the latter spring-actuated, the adjustable terminal stop 9 upon said stem, and the weighted float freely moving thereon and adapted, when in contact with said step, to open the valve, substantially as herein stated.

In combination with a whistle or other alarm 3, the fixed tubular rod 2, its openings 8 S, the adjustable collar 12, the valve 5, valvestem 6, and. terminal stop 9, the spring 1-1, which holds the valve closed, and the wei hted float upon the valve-stem, free to contact with the stop 9 to open the valve when the water-level is at the danger-point, substantially as described.

4. A lowwater-alarm apparatus fol-boilers, consisting of a fixed tubular rod, a valve and valve-stern movable endwise therein, a spring which closes said valve, an adjustable weighted float moving freely upon the valve-stem, the tube extending through said float and open atboth ends, and a stop upon the valvestem, substantially as specified and stated.

In testimony whereof I ailix my signature in presence of two witnesses.

WILLIAM I. PAGE.

\Vitnesses:

JAMES R. BnooK, II. E. Lonon. 

